Any lawn pro's with some advice?

Thanks for all the tips guys. I'm hoping to implement some of these ideas so I can mow my lawn with my rider without feeling like I just got beat up because of how bumpy it is. So what's the deal with "sandy soil" as the leveler? Do I just mix sand with the dirt? We have real good black dirt around here. So, Spread the dirt, roll it, aerate it, then seed it?